<?php
$array=array(
    array(4,5,6,10),
    array(1,2,3),
    array(7,8,9,10,11)
);
foreach($array as $key=>$value){
    if(count($value)>3){
        unset($array[$key]);
        continue;
    }
$array[$key]['sample']=array(1,2,3,4);


}
$array=array_merge($array);
echo "<pre>";
print_r($array);
echo "</bre>";

?>